Introduction

The data used in this document was obtained for 2003-2019 from Environment Canada’s National Air Pollution Surveillance Program (NAPS) (EC NAPS Data). As of May 5, 2021, the data for 2020 has not be uploaded.

The following document reproduces the work by Dabek-Zlotorzynska et al. (2011) and extends the analysis to 2019. The document begins by outlining the NAPS stations and available data. Then the number of daily observations per site are used to calculate a dividing date - the date that approximately divides the total observations in half. Plots are constructed to present the data before and after the dividing date.

Summary of cities and change of stations

The following table summarizes the available spectation data for the selected sites. Information on the NAPS stations was found at the following link; NAPS Station Information

Station Summary of spectation data Change of Stations
Burnaby (S100119 Data for all years No
Abbotsford (S101004) Missing in 2011 Station changed from S101004 (2003 - 2010) to S101005 (2012+)
Golden (S103202) Data from 2004-2007 No information on station closing/changing
Edmonton (S90132) Missing from 2003-2005 No
Windsor (S60211) Missing in 2003 No
Simcoe (S62601) Missing 2003-2004 No
Toronto (S60427) Missing after 2018 Station changed from 60427 (2003-2014) to 60439 (2015 - 20/06/2019) to 60445 (21/06/2019 +). Stations 60439 and 60445 were open in 2019 but are missing PM25
Saint-Anicet (S54401) Missing after 2018 No
Montréal (S50104) Missing after 2008 Station changed from 50104 (2003-2008) to 50134 (2008+). New station does not collect PM 2.5 spec
Canterbury (S40801) Missing after 2009 Stopped site in 2014, did not combine with another station
Halifax (S30113) Station opened in 2006 Station was combined with 30118 (1990-2018) but did not measure PM 2.5 spec

Timeline of stations

The following plot shows the timelines of the available NAPS data for the three different sampler types (spectation, dichotomus and PM 2.5 air). Hovering over a bar will display the name of the sampler.

Figure 1: Timelime of station samplers

Finding the cutoff date

Using six month increments, the dividing date was determined as; 2010-07-01. The following table presents the number of samples before and after the calculated date.

City Number samples before cutoff Number samples after cutoff Percent before cutoff Percent after cutoff
Abbotsford 832 723 0.5350482 0.4649518
Burnaby 918 825 0.5266781 0.4733219
Canterbury 522 94 0.8474026 0.1525974
Edmonton 536 1233 0.3029960 0.6970040
Golden 440 NA 1.0000000 NA
Halifax 329 1255 0.2077020 0.7922980
Montréal 743 566 0.5676089 0.4323911
Saint-Anicet 938 654 0.5891960 0.4108040
Simcoe 650 1173 0.3565551 0.6434449
Toronto 1032 788 0.5670330 0.4329670
Windsor 561 1224 0.3142857 0.6857143

The average of the percent before cutoff column is 0.529 and the percent after cutoff column is 0.519.

Figure 2: Total \(PM_{2.5}\) mass by site

Figure 2: Total $PM_{2.5}$ mass (Median, 25th and 75th percentile, 2nd and 98th percentile)

Figure 2: Total \(PM_{2.5}\) mass (Median, 25th and 75th percentile, 2nd and 98th percentile)

Figure 3: Monthly mean \(PM_{2.5}\) mass by site

Figure 3: Monthly mean $PM_{2.5}$ (Mean and 90th percent CI)

Figure 3: Monthly mean \(PM_{2.5}\) (Mean and 90th percent CI)

Figure 4: Mean organic carbon (OC) by site

Figure 4: Mean Organic Carbon by cartridge and site

Figure 4: Mean Organic Carbon by cartridge and site

Figure 5: Reconstructed \(PM_{2.5}\) mass by major component and site

When calculating the major components, observations from the spectation sampler were used. For a given day, if the spectation observations were missing, and the site had pm 2.5 sampler observations (PM2.5 Manual Air Sampler) was used. This affected the observations for Montreal and Canterbury from 2010-2019.

Figure 5: Reconstructed $PM_{2.5}$ mass by compound mean

Figure 5: Reconstructed \(PM_{2.5}\) mass by compound mean

Figure 6: Reconstructed \(PM_{2.5}\) mass by 10 highest mass days and site

To generate the following figure, the days with the largest \(PM_{2.5}\) mass that had observations for all reconstructed components were used. (i.e. there were days that had larger masses than used, but were missing observations)

For July 2010 - 2019, Golden, Montreal and Canterbury contained at least one missing observation each day.

Figure 6: Reconstructed $PM_{2.5}$ mass by mean compound for the 10 hightest mass concentration days

Figure 6: Reconstructed \(PM_{2.5}\) mass by mean compound for the 10 hightest mass concentration days

Figure 7: Median ammonium sulphate and ammonium nitrate concentrations by site and month

Figure 7: Ammonium sulphate and ammonium nitrate concentrations by site and month (mean and inter-quartile range)

Figure 7: Ammonium sulphate and ammonium nitrate concentrations by site and month (mean and inter-quartile range)

Figure 8: Median elemental carbon (EC) and organic matter (OM) concentrations by site and month

Figure 8: Elemental carbon (EC) and organic matter (OM) by site and month (mean and inter-quartile range)

Figure 8: Elemental carbon (EC) and organic matter (OM) by site and month (mean and inter-quartile range)

Figure 9: Median soil and sodium chloride concentrations by site and month

Figure 9: Soil and sodium chloride concentrations by site and month (mean and inter-quartile range)

Figure 9: Soil and sodium chloride concentrations by site and month (mean and inter-quartile range)

Figure 10: Ammonia mixing ratio by site and month

Figure 10a: Ammonia mixing ratio by site and month (mean and inter-quartile range)

Figure 10a: Ammonia mixing ratio by site and month (mean and inter-quartile range)

Figure 10b: Ammonia mixing ratio for Abbotsford by month (mean and inter-quartile range)

Figure 10b: Ammonia mixing ratio for Abbotsford by month (mean and inter-quartile range)

Figure 11: Median sulphr dioxide mixing ratio and nitric acid concentrations by site and month

Figure 11: Sulphr dioxide mixing ratio and nitric acid concentrations by site and month (mean and inter-quartile range)

Figure 11: Sulphr dioxide mixing ratio and nitric acid concentrations by site and month (mean and inter-quartile range)

References

Dabek-Zlotorzynska, Ewa, Tom F. Dann, P. Kalyani Martinelango, Valbona Celo, Jeffrey R. Brook, David Mathieu, Luyi Ding, and Claire C. Austin. 2011. “Canadian National Air Pollution Surveillance (Naps) Pm2.5 Speciation Program: Methodology and Pm2.5 Chemical Composition for the Years 2003–2008.” Atmospheric Environment 45 (3): 673–86. https://doi.org/https://doi.org/10.1016/j.atmosenv.2010.10.024.